Come on Wouter, there is a reason why it is called the Global Challenge and why it is not an International Class. There are not enough boats in enough countries to be an International class.
You will need to be honest with yourself if you want to grow the class.
2009 US Global Challenge
24 boats
4 non American boats, 2 of them Goodalls
2007 UK Global Challenge
13 Boats
1 non European boat
2008 NL Global Challenge
17 boats
Australian Championships, 8 boats
OK fleets, but still a lot to build on. In AUS, you do not see many F16s, let alone fleets or divisions at regattas. Sounds like it is a common scenario around the world.